MEMS type Temperature and Humidity Sensor (Model: WHT20) Manual Version: V1.4 Date: 2022.6.13 Zhengzhou Winsen Electronics Technology Co., Ltd

Statement This manual copyright belongs to Zhengzhou Winsen Electronics Technology Co., LTD. Without the written permission, any part of this manual shall not be copied, translated, stored in database or retrieval system, also can’t spread through electronic, copying, record ways. Thanks for purchasing our product. In order to let customers use it better and reduce the faults caused by misuse, please read the manual carefully and operate it correctly in accordance with the instructions. If users disobey the terms or remove, disassemble, change the components inside of the sensor, we shall not...

Zhengzhou Winsen Electronics Technology Co., Ltd WHT20 MEMS type Temperature and Humidity Sensor Overview WHT20 is embedded in a dual-row flat no-lead SMD package, which is suitable for reflow soldering, with 3.0x3.0mm bottom surface and 1.0mm height. The temperature and humidity signals can be read on different pins. The sensor outputs calibrated digital signals in standard IIC format. WHT 20 is equipped with an ASIC chip, a MEMS capacitive humidity sensor and a temperature sensor. WHT 20 temperature and humidity sensors have been calibrated and tested on factory, and have excellent reliability...

Zhengzhou Winsen Electronics Technology Co., Ltd Figure 1 Maximum error of relative humidity at 25°C Technical parameters of temperature stable2. temperature characteristic Parameter Accuracy error Prolonged Drift Figure 2 Temperature typical error and maximum error Tel: 86-371-67169097/67169670 Email: [email protected] Leading gas sensing solutions supplier i

Zhengzhou Winsen Electronics Technology Co., Ltd Suggested working environment The recommended temperature and humidity range of this sensor is 5~60℃ and 20~80% RH, as shown in Figure 3. Long-term exposure in the non-recommended range, such as high humidity, may cause temporary signal drift (for example, >80%RH, drift +3% RH after 60 hours). After returning to the recommended range environment, the sensor will gradually return to the calibration state. Long-term exposure to the non-recommended range may accelerate the aging of the product. Figure 3 Working scope RH accuracy at different temperatures...

Zhengzhou Winsen Electronics Technology Co., Ltd Electrical specifications (Table 3) Condition Measure Dormant Measure Average Dual-line digital interface, standard I 2C protocol The power consumption given in Table 3 is related to temperature and supply voltage VDD. See Figures 5 and 6 for power consumption estimates. Please note that the curves in Figures 5 and 6 are typical natural characteristics, and there may be deviations. Fig. 5 Typical supply current vs. temperature curve (sleep mode) when VDD=3.3V. There is a deviation of approximately ±25% between these data and the displayed value....

Zhengzhou Winsen Electronics Technology Co., Ltd Package information Tape package Note: 1. This accuracy is the test accuracy of the sensor at 25℃ and the supply voltage is 3.3V during the factory inspection. 2. The time required to reach 63% response under the conditions of 25°C and 1m/s airflow. 3. Normal working range: 0-80%RH, beyond this range, the sensor reading will be biased (after 200 hours under 90%RH humidity, drift <3%RH). The working range is limited to -40-80℃. 4. If there are volatile solvents, tapes with pungent odors, adhesives and packaging materials around the sensor, the readings...

Zhengzhou Winsen Electronics Technology Co., Ltd Application Guide 1.1 Storage Conditions The temperature and humidity sensor should not be exposed to volatile chemicals, such as organic solvents or other inorganic compounds, otherwise it will cause irreversible drift in humidity output readings. it is recommended to store the sensor in the original packaging including a sealed ESD bag, and meet the following conditions: temperature range 10℃-50℃ (within a limited time 0-85℃); humidity 20-60%RH (without ESD package sensor). For those sensors that have been removed from the original packaging,...

Zhengzhou Winsen Electronics Technology Co., Ltd 1.5 Materials for Sealing and Encapsulation To avoid the response time and hysteresis increase caused by the moisture absorption of the surrounding materials, the following materials are recommended: metal materials, LCP, POM (Delrin), PEEK, PVDF, PTFE (Teflon), PP, PB, PPS, PSU , PE, PVF. It is recommended to use epoxy resin to encapsulate electronic components, or silicone resin. However, the gas released by the packaging material may also contaminate WHT20 sensor. Therefore, the final assembly of the sensor should be done in a well-ventilated...

Zhengzhou Winsen Electronics Technology Co., Ltd Figure 8: Recommend WHT 20 PCB design size (unit: mm) For solder printing, laser cutting stainless steel mesh with electronic polishing trapezoidal wall is recommended, with recommended thickness of 0.125 mm. The steel mesh size of the pad should be 0.1 mm longer than PCB pad and placed 0.1 mm away from the packaging center. Steel mesh with bare pads must cover 70% - 90% of the pad area - that is, the central position of the heat dissipation area reaches 1.4 mm x 2.3 mm. Due to the low SMD mounting, it is recommended to use no-cleaning type3 solders...

Zhengzhou Winsen Electronics Technology Co., Ltd Interface Definition Remain suspended Power supply voltage, 2.0~5.5V power supply, recommended voltage of 3.3V I2C serial clock, two-way, for Synchronous Communications between the microprocessor and sensor I2C serial data, SDA, for data input and output of the sensor Power ground Remain suspended Note: 1. To prevent the current from being poured into the signal line (SCL/SDA) by the leakage current, which may lead the chip in a non-working state after power-on, VDD should be powered on prior to or synchronized with SDA and SCL. 2. To ensure communication...

Zhengzhou Winsen Electronics Technology Co., Ltd I2C interface voltage Electrical characteristics, such as power consumption, high and low voltages of input and output, etc., depend on the power supply voltage. Table 6 DC characteristics of digital input and output pads, if there is no special statement, VDD=2.0 V to 5.5 V, T =-40 ℃ to 85℃ Parameter Condition Min Typ. Max Unit VDD = 3.3 V VOL 0 0.4 V Low output voltage Reverse current 3mA VOH High output voltage High output voltage Output sink current Input current ±1 I2C interface timing Table 7 Timing characteristics of I2C fast mode digital...